Why you need to flush the power steering system
The long-lasting and correct operation of a hydraulic power steering system depends on manyófactors. One of the main ones is the condition of the lubricant in the system, under pressure, which transmits torque from the pump to the pistons inside the power steering cylinder. Vehicle operating regulations require this fluid to be changed approximately every 100,000 kilometresóy. However, sometimes one replacement is not enough – the lineód is clogged again. Why does this happen and how can it be avoided?
When and how to change the oil in the power steering system
Most modern carsód are equipped with power steering systems. These can be divided into three groups:
- Hydraulic power steering.
- Electric power steering.
- Electrical power steering.
The difference between electrohydraulic amplifiers and simple hydraulic systems lies in the principle of driving a pump that increases the pressure in the line. In conventional HPCs, it is driven by a belt from the crankshaft pulley of the car engine. In an EGR pump, the pump is electrical, controlled by an electronic unit or board thatóra receives signals from sensorsól and the ECU. However, in both cases the system uses a fluid - usually gear oil, similar to that used in automatic transmissionsów.
Despite longómaintenance intervals, the driver must constantly monitor the lubricant level in the power steering break tank. The fluid must be replaced if it loses itsóworking condition, signs of this will be as follows:
- darkening;
- presence of impurities (swirlsóry, rust, flakes);
- burning smell;excessive wateriness or, conversely, excessive density;
In many cases, the condition of the lubricant should be considered, among other things, as an indicator of system malfunction. Along with its replacement, it will be necessary to eliminate the causes that have caused the premature deterioration of the fluid. As a rule, this is due to failures in the internal parts of the pump (vanes, gearsócks, etc.) or breaches in the tightness of the hoses and main line pipes.
Although manufacturers do not require caróve owners to flush the hydraulic power steering system during an oil change, it is advisable to perform this procedure, especially if the fluid has previously failedód as it is usually plugged from the outside. It is unlikely that you will be able to remove all the contaminants along with the old grease, and the residue is likely to remain in the line. Each time it is replaced, metal swirlsód, clots of old grease and small particles of dirt accumulate inside.
In addition, the new grease can flush out and distribute all this sludge in the system, which risks not only reducing the quality of the grease, but also clogging the working components: power steering pump valve, distributor ductsós, Teflon parts of the rails, which can ultimately lead to hydraulic failure. To prevent this, flushing the hydraulic system is recommended.
How to flush the power steering system
It is unlikely that you will be able to flush the power steering line yourself, this requires the conditionsóof a service station. Above all, this can only be done with a special stand. Flushing it yourself using improvised meansós may lead to damage to the systemós components: pump, hydraulic cylindersós and other assembliesós. To use this service, it is better to contact a qualified workshop: for example STS, which has a professional station for cleaning hydraulic systems.
The special flushing station simulates the action of a hydraulic booster pump and is therefore connected to the high-pressure and return hoses. Like a pump, it pumps working fluid into the system at high pressure. Moving cyclically, the lubricant washes away all deposits inside the line, passing through a two-stage filtration inside the station. The coarse filter, made of copper-coated mesh, traps large fractions of dirt, while the fine filter, whichós a felt sponge, traps small metal particles and other contaminants.
The mechanic's job is not limited to connecting the rack. During the flushing process, the machine must be actively assisted: turn the steering wheel from the extreme right position to the extreme left position, so that the rail bar moves and the fluid flushes the entire interior. At the end of the procedure, the old grease must be completely drained and the lineód be filled with fresh grease. The wyróing reservoir most often needs to be replaced, as its filter mesh is often not removed.
The machine's functions are not limited to flushing: at the same time, the stand diagnoses the steering gear itself: it reads its indicators, monitors pressure and the operation of the distributor. In this wayób after flushing, the entire power steering system becomes virtually identical to a new one - both in terms of performance and remaining service life.
